Please take note --» means "which implies that. Have you ever wondered how ships(very massive) float while stones of very little mass can't. well the concept of flotation is being governed by the law of flotation which states that "for a body to float in a fluid. the weight of the object acting downwards must equal the weight of liquid displaced(up thrust u)", where weight of liquid displaced =u=W1-W2 where W1 Is the weight of object in air, W2 is the weight of object in fluid, therefore if according to law of floatation U=W1 for object to float. therefore substituting for U as W1,W1=W1-W2--»W1-W1=-W2 »O=W2 therefore for an object to float in water the weight of the object in water W2 must equal zero and this is the reason why swimmers feel weightless in water,it is in accordance with the law of floatation Then if this is true why does a ship float in water even with its large mass? Ans:It is due to the shape of the ship, the ship is designed in such a way that it displaces a large volume of water since upthrust U=volume of object*density of liquid*g,where g is acceleration due to gravity10m for the object the float it must have less density to have a large volume to displace enough water to float,since volume=massdensity therefore upthrust U= massofobject*density of liquid*g. And this is the reason why massive bodies like ships float while less massive bodies like stones don't so for a body to float it depends on 1. The shape of object 2.the density of object